Use two leading spaces to create monospaced code on this site, like so:

  import sys
  sys.set_int_max_str_digits(0) # Allows for printing very large numbers
  x = (2 ** 136_279_841) - 1
  print(x)

Also, note that 1 << 136_279_841 is much faster than 2 ** 136_279_841; the former runs in <10ms, while the latter takes over 600ms on my machine (a 60x difference).